The present invention relates to an air-cushion vehicle comprising a hull, two air propulsion units located at a considerable distance from each other and one or several drive engines for said propulsion units.
Previously known air-cushion vehicles comprise a hull and one or several propulsion units. These units are located either close to the longitudinal axis of the vehicle or symmetrically at both sides thereof in the front or the rear of the vehicle. Turning of the vehicle is obtained, for example, by means of one or several side rudders as shown in U.S. Pat. No. 4,046,215. When the propulsion units are located symmetrically at both sides of the longitudinal axis of the vehicle, steering can also be carried out by varying the output power of one or several of the propulsion units.
Because of the location of their propulsion units, prior art air-cushion vehicles generally have relatively poor steering characteristics as well as inefficient cargo space. The steering response of the vehicle at low speeds is usually poor, when the propulsion units are located close to the longitudinal axis of the vehicle. At high speeds the response is better, but there is then considerable sideway sliding in curves. If the propulsion units are located symmetrically on both sides of the longitudinal axis in the front as well as in the rear of the vehicle, a good steering response can be obtained also at low speed. However, then at least four propulsion units are needed. This is expensive, and furthermore, the load capacity and the free deck area of the vehicle are considerably reduced.